Answer
$C\cup E= \{ 1,3,5,7 \}$
Work Step by Step
$\bf{\text{Solution Outline:}}$
To get the elements of $
C\cup E
,$ combine all the elements of $C$ and $E$.
$\bf{\text{Solution Details:}}$
The union of $C$ and $E,$ given by $C\cup E$, is the set that contains the combined elements of $C$ and $E$.
With $
C=\{ 1,3,5,7 \}
$ and $
E=\{3,7\}
$ then
\begin{array}{l}\require{cancel}
C\cup E= \{ 1,3,5,7 \}
.\end{array}
